NASA says the observations show for the first time that the waves travel on magnetic field lines connecting Saturn directly to Enceladus. Researchers say the lines act like an electrical circuit, causing energy to flow back and forth between the planet and its moon.

Cassini detected electromagnetic waves in the audio frequency range and, just as radio turns those waves into music, scientists have turned the waves Cassini found into sounds. NASA released a 16-minute recording that was compressed into 28.5 seconds.

NASA says Saturn and Enceladus react differently to each other than Earth to our moon because Enceladus is inside Saturn’s magnetic field. Enceladus is also geologically active, and plumes of water vapor it erupts become ionized and fill the environment around Saturn.